Parametric on-line fault location methods for distribution MV networks

This paper describes two parametric methods for on-line phase-to-ground fault location in distribution medium- voltage networks with isolated or compensated neutral. The first method is based on allocating the upper frequency (f
₂
) of free oscillations caused by the faulted phase capacitance discharge in the transient process of earth fault. The allocated frequency and frequency response l
_F
=phi(f
₂
) calculated for the damaged line are used to locate the fault. The second one is based on the analysis of transient voltages at the initial moment of insulation breakdown. As the parameter defining the distance to a fault point it is offered to use the maximum voltage derivative. The field tests have shown the application capability of the methods with reference to radial distribution networks 10 kV.